Immersion responsive trigger mechanism

ABSTRACT

AN IMMERSION RESPONSIVE TRIGGER MECHANISM IS PROVIDED WHICH INCLUDES A NORMALLY CLOSED HOUSING HAVING A CORD EXTENDING FROM ONE END AND A CONNECTING RING AT THE OTHER END. A PISTON IS PROVIDED IN THE HOUSING   MOVABLE IN RESPONSE TO PREDETERMINED WATER PRESSURE FOR PERMITTING WATER TO ENTER THE HOUSING AND EFFECT THE QUICK DISINTEGRATION OF A LINK TO RELEASE THE CORD.

June 1971 I A. M. LAVIN 3,581,352

IMMERSION RESPONSIVE TRIGGER MECHANISM Filed Dec. 19, 1969 FIG.

INVENTOR AARON M. LAV/N ATTORNEY United States Patent IMMERSION RESPONSIVE TRIGGER MECHANISM Aaron M. Lavin, Upper Moreland Township, Montgomery County, Pa. A. M. Lavin Machine Works, Inc.,

Davisville Road and Pennsylvania R.R., Hatboro, Pa.

Filed Dec. 19, 1969, Ser. No. 886,493 Int. Cl. F16g 11/00 U.S. Cl. 24--123 9 Claims ABSTRACT OF THE DISCLOSURE An immersion responsive trigger mechanism is provided which includes a normally closed housing having a cord extending from one end and a connecting ring at the other end. A piston is provided in the housing movable in response to predetermined Water pressure for permitting water to enter the housing and effect the quick disintegration of a link to release the cord.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to an immersion responsive trigger or release mechanism.

Description of the prior art Trigger mechanisms or safety links releasable upon immersion in water have heretofore been proposed. A common type of releasable element heretofore proposed includes a solid crystalline material which dissolves relatively slowly upon immersion in water and with a solution rate determined by the temperature of the water.

The devices heretofore proposed have not proven wholly satisfactory and this may be due at least in part to the time required to dissolve the material before release can be effected.

The structure of the present invention is quick acting when required and is not subject to the difficulties heretofore encountered with such safety links.

SUMMARY OF THE INVENTION In accordance with the invention an immersion responsive trigger mechanism is provided having a protective enclosing housing with a piston therein normally held in protective position by a spring and which piston upon subjection to a predetermined pressure, optionally of the order of several inches or several feet of water, is moved to a position to permit water to enter the housing, effect the rapid disintegration of a link and release a cord or the like.

It is the principal object of the invention to provide an immersion responsive trigger mechanism which is simple in construction, compact, reliable in its action and which will have a long useful life.

It is a further object of the present invention to provide a trigger mechanism of the character aforesaid which is adapted for a wide variety of uses where quick release of an article, such as a boat or raft, is desired when another article on which the first article is carried or connected sinks or is otherwise immersed to a predetermined extent.

It is a further object of the present invention to provide a trigger mechanism of the character aforesaid which is rapid in its releasing action.

Other objects and advantageous features of the invention will be apparent from the description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS The nature and characteristic features of the invention will be more readily understood from the following de- "ice scription taken in connection with the accompanying drawings forming part thereof, in which:

FIG. 1 is a longitudinal central sectional view through a preferred embodiment of the invention;

FIG. 2. is a transverse sectional view, enlarged, taken approximately on the line 22 of FIG. 1; and

FIG. 3 is a transverse sectional view, enlarged, taken approximately on the line 33 of FIG. 1.

It should, of course, be understood that the description and drawings herein are illustrative merely and that various modifications and changes can be made in the structure disclosed without departing from the spirit of the invention.

Like numerals refer to like parts throughout the several views.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more particularly to the drawings in which a preferred embodiment of the invention is illustrated, a cylindrical housing 10 is provided having an outwardly extending rim 11 at one end.

The opposite end of the housing 10 is internally threaded as at 12 for the reception of a complementally threaded plug 13 which carries a ring 14 for attachment of the trigger mechanism to an article with which it is to be used.

The housing 10 has, contiguous to the plug 13, a plurality of openings 15 for access of water.

The housing 10 has remote from the rim 11, an inwardly extending rim 16 which serves as a stop and for the attachment of a screen 17 which reduces the impact effect of water entering the openings so that the pressure of the water entering the housing 10 at this location will be the effective agency.

The housing 10, in spaced relation to the rim 16 has a portion 19' of enlarged diameter.

A transverse bracket 20 engaged at its ends 21 in the enlarged portion 19 has a mounting bracket 22 disposed in the housing 10 engaged therewith.

A piston 25' is provided in the housing 10 movable toward and away from the stop rim 1-6 and normally urged to seated position on the stop rim 16 by a compression spring 26 which engages the bracket 20 and the piston 25.

The piston 25, is loosely fitted within the housing 10 and has a packing 27, such as an O-ring which normally and with the piston 25 in seated position on the rim 16 prevents fluid flow past the piston 25. The piston 25 is movable, by application of fluid pressure thereon to a position at the enlarged housing portion 19 so that liquid can pass the piston 25 and enter the space thereabove.

A piston guide rod 28 is provided, secured to the piston 25 and extending through aligned guide openings 29 and 30 in the brackets 20 and 22.

The end of the housing 10 at which the rim 11 is located is closed by a closure cap 33 which has a central opening 3 4 with a sleeve extension 35 therearound and a packing groove 36 at the outer end of the opening 34. A boot 38, preferably of rubber or the like is engageable on the rim 11 and has a terminal end 39 with the interior of which a flat washer 40 is in engagement. A compression spring 41 bears at one end on the washer 40 and at the other end on a packing 42, such as an O-ring, which is seated in the groove 36 to prevent fluid access at this location.

A cord 45 is provided preferably of braided nylon and extends into the interior of the housing 10 and a metal sleeve 46 is secured thereto by a reduced neck portion 47 with suitable potting material inserted to prevent leakage. The sleeve 46 where it enters the opening 34, is engaged by the packing 42 to prevent fluid leakage at that location.

A transverse post 48 is secured in the housing between the end cap 33 and the bracket 22, and around which the cord 45 is disposed with the appropriate number of turns 45a. in accordance with the frictional holding or mechanical advantage desired. A positioning pin 49 carried by the post 48 locates the cord 45 in its relation to the opening 34 and thereby controls the positioning of the cord 45 on the post 48 and thus provides a better control of the frictional force.

The free end of the cord 45 has a link 50 secured thereto by a connection 51 of any desired type such as adhesive or heat sealed, but of an external size and diameter such that it can freely pass through the opening 34.

While the link 50 can be of any desired material it is preferred that it be of felted or paperlike material, carbonmethyl cellulose in a thickness of 7 mils, being particularly suitable because of its normal dry strength, and its exceedingly rapid and complete disintegration in or upon submergence in water.

The other end of the link 50 is secured to the mounting bracket 22 in any desired manner. One suitable securing connection consists of a holding arm 52 of resilient material, secured to the bracket 22 at one end by a rivet 53. A clearance opening 54 is preferably provided for the guide rod 28. The other end of the arm 52 is curved as at 55 for disposition therearound of the link 50 in a manner to prevent shearing or tearing of the link 50. The holding arm 52 is held in clamping engagement with respect to the end of the link 50 by a clamping screw 56 which extends through the bracket 22 and is threaded into the arm 52 for drawing it down into clamping relation to the end of the link 50.

The mode of operation will now be pointed out.

The trigger mechanism has the cord 45 connected to one of the devices which is to be releasably secured to the other, the ring 14 being connected to the other device. The orientation of the trigger mechanism is not critical and it may be horizontal, tilted or inverted.

Upon immersioin of the trigger mechanism in Water, water will enter through the openings 15, and will be effective through the screen 17 against the piston 25.

When the force exerted on the piston is sufficient to overcome the force exerted by the spring 26 the piston 25 will be moved to the enlarged portion 19 of the housing 10 and water will enter the interior space in the housing 10 and will contact the link 50, causing the link 50 to disintegrate so that the inner end of the cord 45 is re leased and will be withdrawn through the opening 34 and through the boot 38, releasing the device which it had previously restrained.

It will be seen that the interior of the bushing 10 in which the link 50 is disposed is sealed by the packing 27 and by the packing 42 against access of moisture which might in time prematurely weaken the link 50.

The movement of the piston 25 is determined by the spring force exerted by spring 26 so that the release point in terms of water pressure can be easily determined by selection of the proper spring 26.

It will thus be seen that structure has been provided with which the objects of the invention are attained.

I claim:

1. An immersion responsive trigger mechanism comprising a housing having an interior portion,

a fluid pressure responsive member in said housing movable in response to liquid pressure thereon to a position for delivering liquid into said interior portion,

a resilient member for opposing movement of said liquid pressure responsive member, a releasable member extending into said interior pornon, a fixed member in said interior portion, and a liquid releasable link connected to said releasable member and to said fixed member normally retaining said releasable member in position but releasing said releasable member upon immersion in liquid. 2. An immersion responsive trigger mechanism as defined in claim 1 in which said housing has a transverse post therein, said releasable member is a cord, and said cord has a portion deposited in a plurality of turns therearound. 3. An immersion responsive trigger mechanism as defined in claim 2 in which said post has a cord turn positioning member carried thereby. 4. An immersion responsive trigger mechanism as defined in claim 1 in which said fluid pressure responsive member is a piston and said piston has a packing for normally preventing liquid flow therebeyond in said housing. 5. An immersion responsive trigger mechanism as defined in claim- 1 in which said releasable member is a cord, said housing has an end portion through which said cord extends, and said cord and said end portion of said housing have a fluid tight packing therebetween. 6. An immersion responsive trigger mechanism as defined in claim 1 in which said liquid releasable link is of carboxymethyl cellulose. 7. An immersion responsive trigger mechanism as defined in claim '1 in which said releasable member is a cord, and said liquid-releasable link is secured at one end to said releasable member. 8. An immersion responsive trigger mechanism as defined in claim 1 in which said fluid ressure responsive member is a piston, said piston has a guide rod extending therefrom, and guide members are provided in said housing with which said guide rod is in engagement. 9. An immersion responsive trigger mechanism as defined in claim 1 in which said fluid pressure responsive member is a piston, said housing has an enlarged portion to which said piston is moved by fluid pressure thereagainst for delivery of liquid past said piston, and said resilient member is a spring engaging said piston and a fixed abutment in said housing.

References Cited UNITED STATES PATENTS 1,294,327 2/1919 Boston & Patrick, Jr. 294-83 3,107,938 10/1963 Schick et al 29483 3,228,080 1/1966 Trauger 24-230 3,262,090 7/1966 Farmer 98 3,314,088 4/1967 Nordhaus et al. 24-230 3,326,226 6/1967 Hinton 98 BOBBY R. GAY, Primary Examiner G. MOORE, Assistant Examiner US. Cl. X.R. 

